Published onOctober 25 2017
As we leave the summer months behind and head into autumn, it’s a good time to review sprayer maintenance and storage. Specifically, what we should be thinking about when hibernating our sprayer through the winter months.
I took my chemical application and knapsack assessment at Brinsbury College back on 6 September, 1988. At that time I was a very inexperienced young greenkeeper studying for my sports turf management qualifications. If you are a qualified sprayer, what I aim to discuss in this article will be familiar information and I hope if nothing more, a refresher of your experience and knowledge.
We are all aware of how our climate is changing, often resulting in warmer winters. However, if we remember back to the winter of 2009, we had record temperatures of -22°C. I remember this time in particular as I was a UK service manager and was experiencing a high volume of sprayer issues when the spring arrived. Nearly all the issues at that time were a direct result of the low temperatures and poor winter maintenance and storage. Luckily, we don’t experience that type of weather on a yearly basis, but correct winter maintenance and storage will ensure the machine is fit for purpose.
I have come across all types and age of sprayers and generally the age of the machine can be irrelevant to achieving good results. This is, of course, providing you have regularly followed a good maintenance regime. Spray techs will fully understand prestart checks, correct calibration process and end of day maintenance. All of these done correctly will ensure the sprayer is fit for purpose - not only helping maintain accurate application rates but also improving the lifetime of the sprayer.
Additionally, with ever stringent legislation on chemical application, following good maintenance practice will ensure that the sprayer can achieve the National Sprayer Testing Scheme standards when inspected by a qualified technician. The NSTS became mandatory for the UK on 26 November, 2016 and applies to anyone using chemical application prime movers. The NSTS satisfies the sprayer testing requirements of the Sustainable Use Directive and I was privileged to be part of this initiative since its concept in 2003. Adopted by the EU, the current EU legislation states that owners of pesticide application equipment which is over five years old and in use must ensure it is inspected at regular intervals. The NSTS website has all the up-to-date information on testing.
Dealing extensively with sprayers over the years, I have found the fundamentals are often overlooked. These basics can affect the application rates, spray consistency and reduce the life of the sprayer, all of which will increase the operational cost of applying chemicals. As we approach the end of the season, it is an ideal time to run through this basic maintenance. If anything needs replacing, you will have time to order and fit new parts, ensuring you’re ready to run at the start of the new season. As always, my advice is to comply with the manufacturers recommendations on winter storage and maintenance. This information will be available in the operator’s manual.
Whether you’re an operator or technician, when working with or on sprayers, we need to consider and use appropriate PPE. Before commencing maintenance work on the machine it should be thoroughly rinsed inside and out three times.
- Clean dirt and grime from the entire machine. Use a tank cleaner to remove as much staining as possible from the tank. NSTS guidelines are for the tank markings to be legible. The machine looks better and encourages good maintenance
- Adding a rust inhibiting, non-alcohol based antifreeze solution to the system will prevent damage from water freezing in the system over winter. Check with the manufacturer as to what it recommends to use. You will need to ensure it is flushed out when you use the machine for the first time after storage
- Grease any bypass valves so that you can easily trim each boom bypass at the start of the season. This is one area that I find is missed. Damage can occur at the start of the season when trying to adjust bypass valves that will not turn freely
- Remove and inspect filters. It has been a common theme for me to find filters either missing, damaged or blocked. I have also found that it is difficult to remove the suction pipe to check the filter due to missed maintenance. I recommend light lubrication around the rubber seal to help future removal of the suction pipes
- Take off the pump head and inspect the pump, check for damage, wear and general debris. Inspect the check valves making sure they are seating correctly. Service intervals vary, but a general rule I apply is to service the pump every two years. If in doubt, check the manufacturer’s recommendations
- Lubricate all grease points on the boom, pump and machine. The pump usually has a grease point to lubricate the internal moving parts. Too often I hear operators and technicians take the view that they will wait for the pump to fail before carrying out maintenance. Remember, preventative maintenance, if not carried out, will affect the application rates, spray consistency and reduce the life of the sprayer, all of which will increase the operational cost
- If fitted, check the pressure dampener. When you release air from the valve, only air should be released. If water and air is released, the diaphragm is damaged and will need replacing. Make sure you add the correct pressure back into the valve. This will depend on your spraying pressure. If in doubt you should refer to manufacturer’s guidelines
- If fitted, check suction dampener for a spongy/floating movement. This will indicate there is fluid behind the dampener which is correct. If a check valve is damaged, an indication of this will be the suction dampener not having that spongy/floating movement
- Check for any leaks by running the machine above normal working pressure and looking for any drips. Generally, we run between 30-50PSI (2-3bar), so running the machine over this working pressure will show any leaks. Use a torch to check all the pipe work and fittings tucked out of sight under the machine. Inspect all pipe fittings and jubilee clips for signs of damage or leaks. It will be easier to replace these at this stage with the machine clean rather than after a field failure with chemical in the system
- Check nozzles for pattern and conformity. This is something we should be doing regularly throughout the season. We should all be aware of the value in doing a catch test on each nozzle. This will check nozzle conformity as well as correct application rate based on litres per minute caught in a jug. If you find a discrepancy of +/- 5% on any nozzle, it is recommended you change the complete set of nozzles.
Ian Sumpter has worked in the amenity horticulture sector for more than 30 years. He now works as a freelance training consultant - both advising on and delivering training. He is on the executive committee of the Institute of Agricultural Engineers as a trustee and is actively involved in developing the industry.
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